Optimal tilt angle determination of photovoltaic panels and comparing of their mathematical model predictions to experimental data in Kerman

Author(s):  
Amin Rouholamini ◽  
Hamed Pourgharibshahi ◽  
Roohollah Fadaeinedjad ◽  
Gerry Moschopoulos
2018 ◽  
Vol 14 (1) ◽  
Author(s):  
Bahador Abolpour ◽  
M. Mehdi Afsahi ◽  
Ataallah Soltani Goharrizi

Abstract In this study, reduction of in-flight fine particles of magnetite ore concentrate by methane at a constant heat flux has been investigated both experimentally and numerically. A 3D turbulent mathematical model was developed to simulate the dynamic motion of these particles in a methane content reactor and experiments were conducted to evaluate the model. The kinetics of the reaction were obtained using an optimizing method as: [-Ln(1-X)]1/2.91 = 1.02 × 10−2dP−2.07CCH40.16exp(−1.78 × 105/RT)t. The model predictions were compared with the experimental data and the data had an excellent agreement.


2002 ◽  
Vol 4 (1) ◽  
pp. 21-38 ◽  
Author(s):  
C. E. Kelly ◽  
R. D. Leek ◽  
H. M. Byrne ◽  
S. M. Cox ◽  
A. L. Harris ◽  
...  

In this paper a mathematical model that describes macrophage infiltration into avascular tumours is presented. The qualitative accuracy of the model is assessed by comparing numerical results with independent experimental data that describe the infiltration of macrophages into two types of spheroids: chemoattractant-producing (hepa-1) and chemoattractant-deficient (or C4) spheroids. A combination of analytical and numerical techniques are used to show how the infiltration pattern depends on the motility mechanisms involved (i.e. random motion and chemotaxis) and to explain the observed differences in macrophage infiltration into the hepa-1 and C4 spheroids. Model predictions are generated to show how the spheroid's size and spatial structure and the ability of its constituent cells influence macrophage infiltration. For example, chemoattractant-producing spheroids are shown to recruit larger numbers of macrophages than chemoattractant-deficient spheroids of the same size and spatial structure. The biological implications of these results are also discussed briefly.


1994 ◽  
Vol 29 (9) ◽  
pp. 151-160 ◽  
Author(s):  
M. Tzitzi ◽  
D. V. Vayenas ◽  
G. Lyberatos

Ozonation of textile industrial wastewaters was examined in CSTR and batch studies. Experiments were done for various types of textile wastewaters and for different reaction and retention times. Much better results were obtained using ozonation after the coagulation-precipitation stage. Also a mathematical model was developed, able to describe wastewater decolonization and COD reduction. In all cases the comparison between the model predictions and the experimental data was satisfactory.


2003 ◽  
Vol 10 (1) ◽  
pp. 37-50 ◽  
Author(s):  
L.F.P. Franca ◽  
M.A. Savi

This contribution presents an investigation on noise sensitivity of some of the most disseminated techniques employed to estimate Lyapunov exponents from time series. Since noise contamination is unavoidable in cases of data acquisition, it is important to recognize techniques that could be employed for a correct identification of chaos. State space reconstruction and the determination of Lyapunov exponents are carried out to investigate the response of a nonlinear pendulum. Signals are generated by numerical integration of the mathematical model, selecting a single variable of the system as a time series. In order to simulate experimental data sets, a random noise is introduced in the signal. Basically, the analyses of periodic and chaotic motions are carried out. Results obtained from mathematical model are compared with the one obtained from time series analysis, evaluating noise sensitivity. This procedure allows the identification of the best techniques to be employed in the analysis of experimental data.


2008 ◽  
Vol 3 (1) ◽  
Author(s):  
Jayakumar Natesan Subramanian ◽  
Farouq S. Mjalli

The heat transfer cooling of a hot liquid in a stirred vessel has been studied experimentally with coolant flowing through a half-coil around the vessel. Correlations have been developed for the heat transfer coefficient of the half coil jacket. A mathematical model for the half coil jacket liquid temperature dynamics and its analytical solution is used to find the shell side temperature profile as a function of time. It is found that the model predictions are in satisfactory agreement with the experimental data and that the developed correlation is superior to previously published correlations for similar systems.


Author(s):  
V. A. Basarab

The article is devoted to determine the technological parameters of soil compaction by rollers according to soil properties in construction. The compaction of the soil occurs due to certain force loads on the soil. Nowadays, there are enough methods to determine the technological parameters of soil compaction process, however, there are few research methods that consider the system of soil-machine-technological parameters. The urgency of the soil compaction process, which ultimately determines the quality of construction products, was emphasized. The basic physical and mechanical properties of soil and technological parameters of the compaction process were given. Analysis of discrete mathematical model of interaction between roller and soil was carried out in order to determine the technological parameters of soil compaction process in the field of construction technologies. A rheological model to describe the soil properties was used. The differential equations of the interaction between roller and soil have been made. A numerical calculation method to solve the differential equations has been proposed. The basic technological parameters of soil compaction process by rollers have been determined - the thickness of soil layer to be compacted, the number of the roller passes, and the speed of the roller movement. The methodology of theoretical and experimental researches of interaction between roller and soil has been proposed in order to clarify the mathematical model and to find the technological parameters of the compaction process. Experimental research methods are based on the determination of the stress-strain state of soil and on the Fourier analysis of the experimental data. Fourier analysis of the experimental data makes it possible to analyze the qualitative energy spectrum of the interaction between roller and soil to determine the rational amplitude-frequency characteristics of the compaction process. Experimental studies allow obtaining such rheological properties of soil as elasticity, viscosity, coefficient of elastic resistance, etc. The main recommendations for the choice of compaction method depending on the type of soil have been proposed.


Author(s):  
А.Ю. Виноградов ◽  
О.В. Зубова ◽  
Е.А. Парфенов

Проведен анализ существующих способов оценки размыва грунтов в гидротехнических и водопропускных сооружениях, показывающий, что определение глубины и скорости размыва проводится без учета физических свойств связных грунтов. Таким образом, данные параметры оцениваются по эмпирическим зависимостям и с существенными погрешностями. Опытные данные по размыву связных грунтов доказывают, что большая удельная поверхность и гидрофильность глинистых частиц приводят к разуплотнению и выносу микроагрегатов грунта в поток. Предложена математическая модель расчета глубины размыва связных грунтов в зависимости от касательного напряжения в грунте. Учет показателей сцепления и угла внутреннего трения в данной модели позволит избежать погрешностей в расчетах. The analysis of existing methods for assessing soil erosion in hydraulic engineering and culverts, showing that the determination of the depth and rate of erosion is carried out without taking into account the physical properties of cohesive soils. Thus, these parameters are estimated using empirical relationships and with significant errors. Experimental data on erosion of cohesive soils prove that the large specific surface area and hydrophilicity of clay particles lead to decompaction and the removal of soil microaggregates into the flow. A mathematical model is proposed for calculating the depth of erosion of cohesive soils depending on the shear stress in the soil. Taking into account the adhesion indicators and the angle of internal friction in this model will avoid errors in the calculations.


2021 ◽  
Vol 939 (1) ◽  
pp. 012052
Author(s):  
A Z Mamatov ◽  
A K Usmankulov ◽  
I Z Abbazov ◽  
U A Norboyev ◽  
E T Mukhametshina

Abstract This article solves one parabolic-type boundary value problem for determining the heat-moisture state of raw cotton in drum dryers at a constant air temperature. Numerical results are obtained by the Bubnov – Galerkin method of the problem under consideration, a comparative analysis is carried out with experimental data. It is shown that the proposed mathematical model and its numerical algorithm adequately describe the drying process of raw cotton.


2021 ◽  
Vol 257 ◽  
pp. 03047
Author(s):  
Zhehua Du ◽  
Xin Lin

A simple mathematical model is proposed to account for emissions of Volatile Organic Compounds (VOCs) from three-layer building materials. The model considers both the diffusion within three layer building materials and the mass transfer resistance through the air boundary layer. A general solution method based on Laplace transform is presented. Compared to other models capable of accounting for emissions of VOCs from multi layer building materials, the present model is fully analytical instead of being numerical. The present model was validated by the experimental data from the specially designed test. The results indicated that there was a good agreement between the model predictions and the experimental data. It can also be seen from calculation that model ignoring the boundary layer resistance cannot fully reflect the real situation.


1991 ◽  
Vol 56 (6) ◽  
pp. 1173-1179 ◽  
Author(s):  
Radim Hrdina ◽  
Igor Čepčiansky ◽  
Hana Bittová

A procedure is suggested for studying the kinetics of photochemical reactions using excitation with polychromatic radiation, where the wavenumber dependence of the intensity of the polychromatic radiation entering the reaction compartment must be known. The observed relative intensities of the polychromatic source are calibrated by ferrioxalate actinometry, selected parts of the emission spectrum being eliminated by insertion of filters. The relative intensities of an HBO 200 high-pressure mercury lamp were measured. For the sake of brevity, the experimental data were fitted by a mathematical model (a polynominal), and only the parameters of the polynomial are presented in a tabular form.


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